text: long
  mix(al1, yu1, yl1)
  long	al1, yu1;
  long	yl1;
  {
  	long	dif, difs, difm, prodm, prod, y1;
  
  	dif = (yu1 + 16384 - (yl1 >> 6)) & 16383;
  	difs = dif >> 13;
  
  	difm = difs ? (16384 - dif) & 8191 : dif;
  	prodm = (difm * al1) >> 6;
  	prod = difs ? (16384 - prodm) & 16383 : prodm;
  	y1 = ((yl1 >> 6) + prod) & 8191;
  
  	return(y1);
  }
  
  